Shadowspawn
In the world of the Wheel of Time series by Robert Jordan, Shadowspawn include a number of species, with varying levels of sentience, that have been created by the Dark One or other agents of the Shadow.
Trollocs
Trollocs were created by Aginor during the War of Shadow, one of the leading biologists of the Age of Legends, by crossbreeding human and animal stock. They are able to interbreed with humans, however the offspring are usually stillborn or do not live long. Trollocs are generally bipedal and humanoid, often with both human and animal features: human eyes but an eagle's beak, for instance, or a bear's paws and claws. They are huge in stature and extremely vicious. They are the basic shock troops of the Shadow.
Trollocs are credited with being able to see better than a man in the dark, however they can be blinded by bright lights. Trollocs are also able to track by scent or sound, and kill for the pleasure of killing.
Trollocs are omnivorous and will eat any kind of meat. They are routinely fed captives taken during battles with humans, which are cooked in large cooking pots. If there are no prisoners then lower-ranking Darkfriends are sometimes fed to the Trollocs instead. Trollocs are known to be lazy and this is shown when Rand al'Thor and Loial sneak past a Trolloc guard in The Great Hunt and reclaim the Horn of Valere from Padan Fain.
Unlike other creatures of the Shadow, Trollocs are social animals and form into clan-like bands, such as Al'ghol (Ghoul), Dhai'mon (Demon), Ghar'ghael (Gargoyle), Ahf'frait (Efreet), Bhan'sheen (Banshee), Dha'vol (Devil), Dhjin'nen (Djinn), Ghob'hlin (Goblin), Ghraem'lan (Gremlin), Ko'bal (Kobold), Kno'mon (Gnome), and Gho'hlem (Golem). Only male Trollocs are allowed to participate in raiding parties. Females are cloistered and remain in the Trolloc camps.
Some trollocs are capable of rudimentary human speech, but usually they converse amongst themselves in their own guttural tongue. Trollocs also have a written script for their language, in the form of angular runes. One trolloc, Narg, spoke to Rand al'Thor in his home in "The Eye of the World".
Trollocs are commanded by the Myrddraal, also known as Halfmen, the Eyeless, Shadowmen, Lurk and Fade. Their command of Trollocs began when the Age of Legends ended and the Forsaken were bound. During the Trolloc Wars, they led the trollocs in battle under the Dreadlords.
The weapons of Trollocs are made at the forges in the valley of Thakan'dar. Some of these weapons leave that place with a stain of evil in the metal. These blades can create wounds that will not heal or illnesses that medicine cannot mend. The weapons they use are often crude and cruel, something which reflect their brutish and war like nature.
Trollocs are hated by wolves, who hunt them and call them "The Twisted Ones".
Myrddraal
Myrddraal are Trolloc offspring, but are throwbacks to human origin (throwbacks to the animal side of their genetic heritage never survive). They are tall and pale, muscular and serpent-quick, but they have no eyes, which does not impair their vision in the slightest. Despite having no eyes they are said to have the vision of eagles in both light and darkness. Myrddraal are most often seen leading groups ("fists") of Trollocs, and sometimes "link" with them to achieve even greater control. However, this comes at a cost—dealing a Myrddraal a killing blow will instantly kill any Trollocs linked to it, even though the Myrddraal itself will not die "until the setting sun".
Myrddraal gain certain powers from the Dark One. They have the ability to cause paralyzing fear with a look and can vanish wherever there are shadows. They have few known weaknesses, one of which is that they do not like to cross running water.
Myrddraal wear black armor with overlapping scales, and black cloaks which do not stir in the wind. In battle a Myrddraal wields his sword with great skill and incredible speed. They are able to move between, or disappear into, shadows, wear cloaks that are constantly still and mirrors only reflect a misty image of them. Aginor, one of the Forsaken and creator of both Trollocs and (inadvertently) Myrddraal, theorized that they were "slightly out of phase with time and reality," but was unable to prove his thesis despite extensive, often fatal, testing. Their blood is acidic and will etch steel if not cleaned off. When killed they thrash around blindly for a time, often still holding their weapons, as if refusing to admit they are dead. They wield swords made at Thakan'dar, the forges on the slopes of Shayol Ghul, which are imbued with the soul of a human. (These humans are usually Borderlanders captured during Trolloc raids.) A Myrddraal's sword causes injuries that are almost always fatal if Aes Sedai Healing is not administered. The swords, however, only have a limited lifetime. Myrddraal have the uncanny ability to instill stark terror in anyone they gaze upon: "The look of the Eyeless is fear." The only things Myrddraal are known to fear are running water, the city Shadar Logoth, the half-Mordeth monster named Padan Fain, and the One Power. Myrddraal, along with Gray Men (see below), are the only known creatures who do not dream. Even Trollocs have dreams.
Myrddraal are hated by the wolves more than any other shadowspawn. They are called the "Neverborn" by the wolves. A whole pack of wolves will willingly die trying to kill one Myrddraal.
Myrddraal have their place in the legend and lore of most of the world's (Randland's) societies, where they are known by many names: Halfmen, the Eyeless, Shadowrunners, Shadowmen, Lurk, Fetch, Fade, Neverborn. In most nations, they are treated about as seriously as bogeymen, but those in the Borderlands or who have had the misfortune to encounter them, know better.
Recently, a Myrddraal (Shaidar Haran) has appeared that seems to be the Dark One's avatar.
Darkhounds
Darkhounds are a race of Shadowspawn used by the Dark One. They are about the size of a small horse and look vaguely like a dog. Darkhounds typically run in packs of ten to twelve, though a pack may be as large as fifty hounds. The saliva of a darkhound is an acid that causes bruising and burns which spread quickly, and a few drops are enough to kill a person. Darkhounds (or at least a subspecies Rand al'Thor fights at Rhuidean) are seemingly solid but if they are chopped into bits the parts liquefy, pool, and reform into the darkhound once again. The darkhound leaves no tracks on dirt, grass or snow; but if it steps on stone it leaves footprints. Balefire is the only reliable way to permanently kill one, though Perrin (with Moiraine in party) fought Darkhounds outside of Illian, and killed one with several arrows to the face.
Darkhounds are created by an existing darkhound consuming the soul of a wolf. The wolves themselves refer to them as Shadowbrothers.
Masuri, a Brown Aes Sedai, has researched Darkhounds and claims to have crossed the paths of seven different packs. She says that the number of packs in existence is in dispute, with some sources saying only seven packs exist, while others claim nine, thirteen, or more. Some ancient sources even state that at the time of the Trolloc Wars, there were "a hundred packs" and "in numbers like unto the nightmares of Mankind." See Crossroads of Twilight for a more detailed discussion.
Gholam
The gholam is another creation of Aginor. Only six, three male and three female, were ever created, and only one is known to have survived the Breaking (preserved in a stasis box). The gholam are among the Shadow's most deadly creatures. Appearing human in form, gholam are extremely strong and they appear to be impervious to most forms of physical injury due to their lack of bones and blood as well as their elasticity. A gholam can slip through the tiniest of cracks due to its lack of bones. Because of their incredible strength, they are able to rip a door off its hinges with one hand. They must regularly consume blood to stay alive; while they prefer human blood, the blood of any living creature will do.
Finally, as their only purpose is to kill channelers, they were made completely immune to the One Power (this may have contributed to their rarity: should these creatures have turned against the Forsaken, they would have been difficult to destroy). Only one thing has been known to injure them: a foxhead medallion, currently in the possession of Matrim Cauthon, caused burns when brought in contact with the gholam.
While not necessarily made of the same material, the gholam and Mat's foxhead medallion are seemingly the only things which absorb the One Power, other than cuendillar (which is said to be strengthened by it, not dispersed/conducted by it).
The concept of the gholam may be related to the Golem of Jewish mythology.
Draghkar
Draghkar are a flying creature of the Shadow, resembling a pale man with large eyes, red lips, and bat-like wings (much like our vampire myths). Like the Sirens of Greek myth, they sing hypnotically to their prey to attract them within near proximity. The Draghkar then sucks its prey's soul out by administering the Kiss. What is left behind of the unfortunate prey is only a shell of its former self. It has been said that, once this process has begun, it is worse to be rescued from a Draghkar's kiss with a partial soul, than to be allowed to die.
Though dangerous when undetected, they are not especially difficult to defeat if one can avoid their song. Their fragile wings and lack of armor or other weapons make them susceptible to direct attack; as such, they are often employed as assassins and scouts, along with Grey Men, to eliminate enemies of the Shadow.
Gray Men
Also known as the Soulless.
A small subset of Darkfriends (of both genders, despite the name) actually donate their souls to the Great Lord. While most Gray Men are men, some women have been "stupid enough even among darkfriends" to give up their soul. They become Gray Men, ordinary-looking folk who are, in fact, very difficult to notice, to the point of 'hiding in plain sight': to a person not specifically looking for one, a Gray Man carrying a knife is about as interesting as an old chair, the eyes will perceive them but the mind will write them off as nothing important. Their ubiquity and unremarkability is their primary asset, as they are sent as assassins against sensitive marks; frequently they do the deed without anyone even realizing they were there. Like the Draghkar, however, they are truly dangerous if overlooked but are still dangerous if noticed. Unlike the Draghkar, the Gray Men are very easy for most people to overlook. In The Dragon Reborn, a Gray Man is sent supposedly to kill Egwene and Nynaeve but is killed, probably by Sheriam or Verin.
Jumara
Created by Aginor, jumara are more commonly known in the Third Age as Worms. They are found in the Blight, where they hunt in packs. They supposedly feel little other than hunger and, occasionally, fear.
It is revealed by Sammael in Lord of Chaos that jumara are supposed to transform when fully grown, though he does not specify the form into which they change. For some reason, the jumara inhabiting the Blight during the Third Age are unable to make this transformation.